Although weight loss among overweight/obese individuals is relatively easy to achieve via low-energy diet, long-term maintenance of weight-loss has been less successful. In order to develop mechanisms for ensuring successful weight loss maintenance, it is important to understand the factors that contribute to both weight re-gain and weight maintenance following weight loss. The proposed study is a continuation of an ongoing study designed specifically to identify factors that contribute to both weight re-gain and successful weight maintenance following weight loss. This study will complete 4 years of follow-up evaluations on an established cohort of weight-reduced premenopausal African-American and Caucasian women. Study participants lost weight with either a low-energy diet protocol, a diet + aerobic training protocol, or a diet + resistance training protocol. Women were evaluated at baseline, following weight loss, and annully thereafter for body composition, fat distribution, physical fitness, total and activity-related energy expenditure (by doubly-labeled water), insulin sensitivity, and a number of risk factors for chronic metabolic disease. Baseline data are available on a total of 327 women; this project will complete the final evaluations on the final 76 women to undergo weight loss. At the termination of this project, 1-4 years of follow-up data will be available on -254women. The Specific Aims of this project are: 1) Assess body composition, energy expenditure, physical fitness, and exercise difficulty annually among the established group of weight-reduced women; identify the extent to which free-living physical activity, exercise difficulty, and resting energy expenditure predict changes in body composition over time; 2) Assess body fat distribution, insulin sensitivity, lipids, and markers of inflammation annually among the established group of weight-reduced women; identify the extent to which total, visceral, and subcutaneous abdominal fat predicted changes in disease risk factors over time; 3) Assess lean body mass distribution (trunk vs limb) annually among the established group of weight-reduced women; identify the extent to which lean mass distribution predicts changes in resting energy expenditure over time; 4) Determine the contribution of ethnicity to observed relationships.